Paving element

ABSTRACT

A method and system for forming asphalt paving blocks for paving roadways, and the paving blocks used for paving roadways. The method comprises mixing asphalt in a stationary mixer, molding it into block-like paving elements, transporting the elements to a construction site and laying the elements to form a roadway. The system for forming the paving blocks comprises a molding press mounted on a trailer connected to a tractor, and storage shelves for storing pallets containing the molded paving elements. The paving elements are plastic-coated asphalt block-like elements. The paving elements have all the advantages of a traditional asphalt surface in terms of noise, but can be produced year-round and away from the construction site.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a method of paving the surface of roads with asphalt material using stationary asphalt mixing material. In particular, this invention relates to a method of paving using asphalt paving elements.

[0003] 2. The Prior Art

[0004] The traditional paving process for roads includes mixing asphalt in stationary mixing installations and transporting it by truck to the paving or laying site. This process has the risk of excessive cooling of the mixed stock during transport. Cooling during transport, which may be intensified by driving wind and precipitation, is extremely disadvantageous for several reasons: First, the asphalt material may harden and can no longer be laid following excessive solidification. Second, regulations do not allow cooling below a limit temperature, which depends on the mixed material. This limits the stationary mixing equipment that can be used for a road-building project to those machines that can be operated close to the construction site.

[0005] Asphalt coatings or pavements for roads have many advantages over pavements made of natural stones or concrete. For example, asphalt is more “foot-” or “step-” friendly because it is not as hard and generates less noise from vehicular traffic.

[0006] Road pavements with continuous top layers made from concrete or asphalt have the drawback that they hermetically seal the ground beneath the pavement against precipitation and prevent natural seepage into the ground. A block or stone pavement, on the other hand, allows at least some of the precipitation to penetrate the ground through the joints in the blocks or stones. This way, some seepage is possible.

[0007] Paving stones or blocks having recesses or free spaces on their laterally abutting surfaces have been recently produced to improve the seepage of precipitation. A pavement made from these blocks lets precipitation seep almost unobstructed into the soil. Quasi-sealing of roadways is successfully prevented in this way.

[0008] However, these paving blocks, while ecologically favorable, have the drawback of generating a significant amount of noise from vehicular traffic as compared to a continuous asphalt or concrete pavement. The joints of the blocks are the primary cause of the noise. Attempts have already been made to produce paving blocks from asphalt to at least partially reduce noise emission. However, these blocks lack adequate dimensional stability.

SUMMARY OF THE INVENTION

[0009] It is therefore an object of the present invention to provide a process for processing asphalt for road construction that can to be transported from a mixing installation to the road over large distances.

[0010] This and other objects are achieved by a paving process comprising shaping mixed asphalt into composite block like surface paving elements, transporting the elements to the road construction or paving site, and laying the elements to form a supporting, stone or block-like composite that is stable enough to withstand vehicular traffic.

[0011] To produce these paving elements, a molding press is installed on a vehicle and is connected to and operated by the vehicle's drive. Hydraulic power transmission is the preferred method for operating the molding press. The vehicle also preferably has shelf systems for receiving pallet magazines in the free loading areas of the vehicle.

[0012] The side surfaces of the asphalt paving element according to the invention that face adjacent paving elements when laid are covered in a plastic material. This plastic material preferably has a sound-absorbing structure. A suitable material is a foamed plastic with open cells such as styrofoam, but other materials could also be used.

[0013] The paving element according to the invention is preferably made in a plastic mold, so that the mold can form the plastic covering. The use of a plastic mold enables the paving element to be made from asphalt, which allows the paving element to retain its dimensional stability during storage in the mold. The plastic used for this purpose can be largely recycled plastic.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

[0015] In the drawings, wherein similar reference characters denote similar elements throughout the several views:

[0016]FIG. 1 shows a top view of a paving element with sixteen sides and a paving element with twelve sides;

[0017]FIG. 2 shows a top view of a pavement comprised of the elements shown in FIG. 1.

[0018]FIG. 3 shows a vehicle for transporting the paving elements having a lattice-like guard railing;

[0019]FIG. 4 shows a side view of a transport vehicle having a molding press and pallet shelf system;

[0020]FIG. 5 shows a side view of a transport vehicle filled with pallets;

[0021]FIG. 6 shows a perspective view of a pallet for holding asphalt paving elements according to the invention; and

[0022]FIG. 7 shows a side view of the pallet shown in FIG. 6 with asphalt paving elements placed thereon.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0023] Referring now in detail to the drawings and, in particular, FIG. 1, there are shown two paving elements 1 and 2 placed adjacent each other and having a common free space 3. Free space 3 allows precipitation water to seep into the ground. Elements 1 and 2 are arranged within plastic molds 4 and 5, which are made from a foam material with open cells. Plastic molds 4 and 5 absorb sound created when vehicles drive across the edges of elements 1 and 2.

[0024] The composite paving according to the invention offers a significant ecological advantage over sealing asphalt or concrete pavements because it allows precipitation water to seep into the ground. In addition, the composite paving according to the invention also offers the advantage of a reduction in noise emission that is usually associated with a continuous asphalt or concrete pavement.

[0025] The pavement according to the invention is not limited to the shapes shown in FIGS. 1 and 2, and its beneficial properties are independent of the shape selected for each paving element.

[0026] Another advantage of the present invention is that the asphalt press on the transport vehicle can operate independent of the location of the vehicle. The vehicle only has to be driven to the mixing installation in order to fill the hopper of the asphalt molding press with hot mixing stock. As shown in FIG. 3, the asphalt molding press 12 may be present on a semitrailer 10 pulled by tractor 11 and receives the hot mixing stock from a chute or a conveyor belt (not shown). It is also possible to feed the asphalt molding press 12 from different mixers via two chutes or conveyor belts with two mixing materials. For example, recycled material may be mixed with fresh material by feeding the two different materials into the molding press 12.

[0027] The stock material is received in molding press 12 with virtually no cooling. Therefore, it is not necessary to provide any energy-consuming heating processes. As the pressed paving elements are transported, the driving wind and precipitation serve to cool the elements which are loaded onto pallets and stacked so that they arrive largely cured at the paving site, with no additional cost.

[0028] In order to increase cooling by the driving wind, stacks of pallets 40, as shown in FIGS. 5 and 6 loaded with paving elements 1 or 2 can be loaded on a second vehicle such as a low bed trailer 20 equipped with lattice-type guard rails 21 as shown in FIG. 4 for preventing the elements from falling out during transport. This structure ensures good ventilation of the elements by the driving wind. The previously known drawback of cooling during transport has been turned into an advantage because the cooled paving blocks can be laid at the construction site.

[0029] In the production process, a mold 13 is filled first and the material is shaken and compressed by molding press 12, shown in FIG. 3. When mold 13 is subsequently lifted, stamps or plungers (not shown), which work from the top as pressure and molding stamps in association with an agitator, may remain in place, and the molded elements are thus maintained on the pallet. The parts of the equipment that contact the asphalt may be sprayed with an anti-sticking agent to facilitate release from the mold. If different materials or different formulas are precessed from two mixers, mold 13 may be partially filled with one material, compressed, and then completely filled with another material and compressed again. This way, recycled materials could be used for the lower part of the asphalt paving element, while fresh material could be used for the top.

[0030] The pallet 40 with the shaped asphalt elements can be moved under the machine toward the back of semitrailer 10, and placed for curing and cooling in a shelf system 15, and then stacked in a space-saving manner.

[0031] Upon arrival at the construction site, the stacks of pallets 40 can be unloaded and paving elements 1 and 2 immediately laid. Alternatively, a stacking or palletizing system as known in the concrete block industry may be used, which pushes the asphalt elements together in both horizontal directions, stacks them and secures them with metal strips on the semitrailer.

[0032] To prevent asphalt elements stacked with such a system from sticking together, separating agents can be sprayed on, or foils such as Teflon paper or the like can be placed between the individual layers.

[0033] The palletizing shelf system 15 may also be mounted on the semitrailer 10 along with molding press 12, preferably in front of the rear axles at the point of gravity of the trailer, so that the finished package with stacked asphalt elements is available as the final product for further processing at the rear of the trailer.

[0034] Fresh asphalt material has a tendency to become deformed under pressure, and in the most unfavorable case, of gluing together. Therefore, like concrete products, layers of asphalt elements cannot be stacked immediately after forming, without the risk of damage. However, if the elements are to be laid immediately, the freshly produced layers must be stacked first. To accomplish this according to the invention, a special pallet 40 as shown in FIGS. 6 and 7 having lateral feet 41 as supporting elements underneath the pallet is used. Feet 41 fit into pockets 43 in a pallet located directly underneath. This way, pallet 40 acts as a bridge, permitting stacking and preventing displacement during transport. Pallets 40 preferably have hollow side rails 44 with insertion openings 45 that allow for the fork of a stacker to be inserted therein.

[0035] Pallets 40 may be made from heat resistant plastic or metal material, which may be cleaned easily or may be coated with anti-sticking material or foil.

[0036] In addition, the pallet may be made with indentations or separation profiles 42 in its bottom surface, in which the individual paving elements may rest next to each other with a small amount of space in between. This space corresponds to the thickness of the bridge of the production mold.

[0037] The asphalt elements 1 and 2 may be laid directly without palletizing them, such as with a vacuum laying head. The vacuum laying head pushes the elements together in two perpendicular directions after lifting them to form a tight layer. This procedure saves three work cycles, namely pushing the elements together, palletizing them and bandaging the stacks. Disposal of plastic foils or galvanized steel strips can be eliminated, thus preserving the environment.

[0038] The system according to the invention permits full use of stationary mixing installations even if they are operated at a great distance from the paving site. Storage space can be saved by the mobile equipment. In addition, the previous drawback of cooling the asphalt during the transport is now turned into an advantage.

[0039] The mobile system for producing the asphalt elements 1 and 2 according to the invention can be transported to each mixing station and favorably located for laying the elements. Moreover, pre-production of the elements is possible during the winter. In contrast, the process of laying continuous asphalt using the prior art methods is prohibited during the winter because of regulation prohibiting paving during the cold months as no technically flawless and economically useful work can be performed during this time of year.

[0040] Accordingly, while only a few embodiments of the present invention have been shown and described, it is obvious that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention. 

What is claimed is:
 1. A method of paving the surface of roads, comprising: mixing asphalt material in stationary asphalt mixing equipment; molding the asphalt material into composite, blocklike layable surface paving elements; transporting the paving elements to a laying site; and laying the elements on the laying site to form a supporting, stone-like composite adapted to withstand vehicular traffic.
 2. The method according to claim 1 , further comprising curing the paving elements by exposing the paving elements to driving wind during transport using lattice-like guard railing elements on a transport vehicle.
 3. The method according to claim 2 , wherein the step of curing comprises placing the paving elements on pallets.
 4. The method according to claim 2 , further comprising applying an anti-sticking agent to the paving elements to prevent the paving elements from gluing together.
 5. A system for producing surface paving elements from asphalt, comprising: a trailer; a tractor connected to the trailer for transporting the trailer; and a molding press installed on the trailer, said molding press being connected to and operated by the drive of the tractor.
 6. The system according to claim 5 , wherein the molding press is connected to the drive of the tractor via a hydraulic drive train.
 7. The system according to claim 5 , wherein the areas of the trailer not occupied by the molding press are equipped for receiving pallet magazines.
 8. The system according to claim 7 , further comprising a shelf system holding empty pallets installed on said trailer, from which individual pallets are automatically removed and transported to beneath the molding press.
 9. The system according to claim 5 , further comprising a steel mold wetted with a lubricant, said mold adapted for lowering onto a pallet underneath said molding press and being filled with asphalt from above.
 10. The system according to claim 9 , further comprising means for lifting the mold after filling with asphalt material so that paving elements are retained on the pallet.
 11. The system according to claim 8 , further comprising means for transporting pallets containing asphalt elements from the molding press to a storage area adjacent the molding press having a shelf system, and stacking said pallets on said shelf system.
 12. The system according to claim 5 , further comprising a separate vehicle with lattice-like guard railings for transporting asphalt-containing pallets.
 13. The system according to claim 12 , further comprising a stacking and palletizing device mounted on said transport vehicle, and adapted to push the asphalt elements together in two horizontal directions, and stack and bandage the elements together.
 14. The system according to claim 13 , wherein the stacking and palletizing device is hydraulically driven by the hydraulics of the transport vehicle.
 15. The system according to claim 8 , wherein each pallet comprises a board having vertical supporting elements and indentations such that said vertical supporting elements engage indentations in another pallet arranged underneath to allow stacking of the pallets and to prevent the asphalt elements from being displaced during transport.
 16. The system according to claim 15 , wherein the supporting elements are feet.
 17. The system according to claim 15 , wherein the pallets have openings that accommodate insertion of the fork of a stacking apparatus.
 18. The system according to claim 15 , wherein pallets are made from a material selected from the group consisting of metal and heat-resistant plastic.
 19. The system according to claim 15 , wherein each pallet has indentations for receiving asphalt elements.
 20. A paving element for paving roadways, comprising a block-like element of asphalt material having a top side, a bottom side, and four lateral sides, said element being coated on all sides with an anti-sticking agent.
 21. The paving element according to claim 20 wherein the anti-sticking agent is a foil.
 22. The paving element according to claim 20 wherein the paving element is made at least in part from recycled material.
 23. The paving element according to claim 22 , wherein a lower part of the element is made from recycled material, and is covered by new material.
 24. The paving element according to claim 20 , wherein the asphalt material contains a rubber aggregate.
 25. The paving element according to claim 20 , wherein the lateral sides of the element are covered in plastic.
 26. The paving element according to claim 25 , wherein the plastic has a sound-absorbing structure.
 27. The paving element according to claim 25 , wherein the plastic is foamed with open cells.
 28. The paving element according to claim 25 , wherein the plastic is a production mold for forming the laying element and remains on the laying element at least around the lateral sides.
 29. The paving element according to claim 25 , wherein the plastic is recycled material. 